Original post: Modeling and Control blog’s Greg McMillan resumes his on-line web seminar / demo series with one scheduled for tomorrow, January 5 at 10am CST / 16:00 UTC. The title is How to Setup and Adjust the Dynamic Compensation of Feedforward Signals. In this demo/seminar (a.k.a. deminar), Greg will explore the adjustment of feedforward delay, lead-lag, and gain for the traditional PID and the smart PID for wireless devices.

To join us live, visit http://bit.ly/JC-LiveMeeting. Computer audio will be available. Should you encounter any difficulties, here are dial in alternatives:

Toll-free: +1 (877) 771-7176

Toll: +1 (225) 383-1099

Participant code: 264679

I’m peeking at some of the slides that he’ll share, and which we’ll post along with Greg’s others in SlideShare. He explains that feedforward is the most common advanced control technique used. Often the feedforward signal is a flow or speed for ratio control that is corrected by a feedback process controller. Flow is the predominant process input that is manipulated to set production rate and to control process outputs (e.g. temperature and composition).

Feedforward is most effective if the loop deadtime is large, disturbance speed is fast and size is large, feedforward gain is well known, and feedforward measurement and dynamic compensation are accurate. Setpoint feedforward is most effective if the loop deadtime exceeds the process time constant and the process gain is well known. Greg shared some of these ideas in a ControlGlobal.com column co-authored with Stan Weiner, Feeding on Feedforward.